Digging Deeper into Enhanced Geothermal Systems: Techno-Economic Simulation of EGS Electricity Generation Development

Abstract

Enhanced geothermal systems (EGS) have the potential to greatly expand the capacity of geothermal energy through the use of hydraulic fracturing. They are a promising source of renewable, non-intermittent electricity generation. This study seeks to characterize the economic feasibility of EGS development. Two software tools in Python have been designed to aid in the techno-economic analysis of this technology. The first program generates contour plots to visualize EGS cost sensitivity to various parameters, such as production flow rate and drilling cost. The second is an algorithm that simulates sequential development of EGS resources based on experience gained over cumulative production. The tools are made to be used with GEOPHIRES, an open-source geothermal LCOE simulation and modeling tool. Results suggest that development of EGS in regions with temperatures higher than 250 degC and depths above 3 km can be economically feasible at costs less than 7.2 cents/kWh in the near future. The building of these initial resources can yield subsequent improvements to drilling cost, power plant cost, and production well flow rate, further driving down costs and allowing for development of additional temperature/depth intervals. Depending on assumptions of initial LCOE thresholds and learning rates, this learning process could potentially unlock several hundred gigawatts-electric (GWe) of EGS electricity generation potential in the contiguous United States.